Although the precise causes for the development of acne have not been fully resolved, it has been established that a combination of at-least the following three factors is involved:—                (a) Excessive production of sebum;        (b) Blocking of the entrance of the hair follicle canals; and        (c) Inflammatory processes caused by excessive development of bacteria.        
One of the causes for excessive sebum production is the increased activity of androgenic hormones, which is typical to teenagers.
The inflammatory response is a reaction to the follicle canal blocking by keratin plugs.
Conventional topical treating methods generally fall into five major categories:                (a) Application of antiseptics preparations such as various types of soaps and the like detergents.                    This method is disagreeable due to sever skin drying.                        (b) Chemical antiseptics such as containing sulfur, which again suffers the disadvantage of skin over-drying.        (c) Compositions such as containing salicylic acid. The disadvantage of these methods resides in causing the skin to become light-sensitive.        (d) Use of vitamin A derivatives commercially known as ROACCUTANE™, CURATANE™, ISOTREX™ and others, which contain tretinoin as active agent.        (e) Antibiotics such as Erythromycin or Benzoyl-Peroxide. Drawbacks and limitations known in connection with other antibiotic medications in the long run may arise including immunity of the body against the efficacy of these drugs.        
Oral administered medications have also been tested, mainly in effort to cure the inflammatory of the sebum glands. However, there were found ineffective for removing the white and black heads of the acne comedones.
Attempted use of the new age antibiotics Tetracycline (e.g. MINOCIN™) again, are bound to cause the generally undesirable side-effects of antibiotic treatments.
Another example of orally administered preparations are derivatives of vitamin A, such as ROACCUTANE™. Although reported quite effective, side-effects such as temporary hair loss, sensitivity to sun blaze and joint aches have been experienced; moreover, routine examinations of lever functions must be followed.
Yet another treatment, confined to females only, is based on restricting the sensitivity to the masculine hormone Testosterone.
In extreme cases of inflammation, the use of cortisone has been recommended, albeit for a limited period only.
Experiments with vitamin B or minerals have proved partially successful in reducing sebum production.
For external, night-time application, medications such as DALACIN™, which is based on clindamycin as an active ingredient have been proposed.
For a comprehensive analysis of the prior art see, e.g., U.S. Pat. No. 5,409,917 (Robinson et al).